1. Field of the Invention
This invention relates to a gas mask with a filter in the air aspiration apparatus and, in particular,to a gas mask with electrically operated aspiration equipment, which sucks in ambient air and forces it into the gas mask, in which the filter is located ahead of the ventilation aspiration equipment.
2. Description of the Prior Art
Gas masks are used in firefighting, for example, or in areas contaminated by toxic or radioactive aerosols. The use of gas masks is extremely important in battlefield or crisis situations, since the gas mask is used to remove the effects of biological or chemical weapons from the air inhaled. The cleaning is accomplished by means of filters, which are primarily active carbon filters.
All the filters of the prior art have a limited operating time. Therefore, the filters must be replaced after they have been in operation for a specified period of time. The length of this service life is defined so that when the filter is replaced, it still retains sufficient filtering capability.
It is difficult, however, to strictly observe and respond within the specified replacement intervals. Moreover, it is uneconomical to simply replace the filter, regardless of the amount of toxin it has absorbed, after it has reached a specified period of operation.